4. Those who earn their living2 through manual labor command good salaries. Labor unions have demanded and had gotten high wages for workers in skilled trades such as carpentry, welding, and various kinds of factory work. Thus the standard of living for these workers is high. The bricklayer probably earns more money thana neighbor who is a college professor. The white-collar worker or professional person may remain lower on the economic scale.1) Who command good salaries?2) Who probably makes more money, a bricklayer or a college professor?3) Who are lower on the economic scale?